I have an original black rotary Nortel from the early 1970s.
The sound and feel are amazing, when you use it you are astonished at how good it sounds.
Also, when the power goes out, it will still ring and work properly.
After divestiture in the early 1980s, AT&T was no longer able to own the equipment and charge rent on it. Around 1986-87, I got a call from Southern Bell telling me that I had to give back the phone, or buy it from them. Either way, I was going to have to buy a phone, and they were not nearly as cheap back then as they are now.
Since I really liked the phone, I asked "How much?" and they said something like $70. "Oh, too much." I said. Then they said, "We can charge $6 to your monthly account for a year." and I agreed to that.
The phone is easily 4 decades old, has taken extraordinary abuse, but is still in perfect condition and the sound is crystal clear.